1. Field of the Invention
The present invention relates to storage bins with material handling conveyors. In particular, it relates to an ice storage bin or receptacle which has a driven conveyor to aid in the discharge of material from the bin.
2. Description of the Prior Art
The automatic and sanitary handling of fragmentary ice in an ice storage bin has historically presented an exceedingly difficult problem. Fragmentary ice stored in a storage bin tends to fuse together and become difficult to move. As a result, fragmentary ice in bulk storage is difficult to handle because it is virtually incapable of flowing out of the bin by gravity. The inability of bulk fragmentary ice to flow by gravity has been recognized and the prior art has employed a device known as an ice rake to facilitate the handling of bulk ice. An ice rake is a type of drag conveyor which contacts the top of a pile of ice and is maintained in contact therewith by cables and weights.
In the past, ice rakes have been constructed so they are positioned horizontally on an ice pile within the bin and serve to remove the fragmentary ice from the top of the pile to a discharge conveyor. Such systems have the disadvantage that they require considerable overhead clearance for the pulleys, cables, and motors required to maintain the ice rake in a horizontal position and to control the movement of the ice rake. In addition, such devices typically require a cumbersome counterweight movement mechanism in order to raise the ice rake to refill the bin with a new supply of fragmentary ice.
A further disadvantage lies in the requirement that most ice handling mechanisms must be constructed particularly for the specific bin in which they are to work. Such custom-made devices are difficult to produce in an economical manner so the cost of manufacturing and installing such devices tends to be very high.
Various bin unloading systems have been proposed for materials other than fragmentary ice; however, many of them are inappropriate for use in the sanitary environment required for the storage and handling of ice. In particular, many of the conveying devices used for other materials have motors and gears located within the storage chamber, which could lead to the introduction of grease or other debris into the ice bin. Bin unloading systems such as these are therefore inappropriate for use in bulk ice storage bins.
Rakes often are raised and lowered by timing devices, and misjudgment of ice flow or ascent of rake arm can bury arms in ice. Thus, there is a need for an ice handling device which can be economically constructed for use in ice storage bins of various sizes in order to provide efficient, sanitary unloading of fragmentary ice. The present invention is directed toward filling that need.